I am not sure myself, but research shows that while it's not a unique expression, it barely gets used... It could be a torture device, at least a chair that you can't get out of. Interestingly, one Japanese artist seems to have used that expression in a song many years ago: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-GT-J35TfTuw.html